window.addEventListener('load', function () {
  function button(label, ariaLabel, icon, className) {
    const btn = document.createElement('button')
    btn.classList.add('btnIcon', className)
    btn.setAttribute('type', 'button')
    btn.setAttribute('aria-label', ariaLabel)
    btn.innerHTML =
      '<div class="btnIcon__body">' +
      icon +
      '<strong class="btnIcon__label">' +
      label +
      '</strong>' +
      '</div>'
    return btn
  }

  function addButtons(codeBlockSelector, btn) {
    document.querySelectorAll(codeBlockSelector).forEach(function (code) {
      code.parentNode.appendChild(btn.cloneNode(true))
    })
  }

  const copyIcon =
    '<svg width="12" height="12" viewBox="340 364 14 15" xmlns="http://www.w3.org/2000/svg"><path fill="currentColor" d="M342 375.974h4v.998h-4v-.998zm5-5.987h-5v.998h5v-.998zm2 2.994v-1.995l-3 2.993 3 2.994v-1.996h5v-1.995h-5zm-4.5-.997H342v.998h2.5v-.997zm-2.5 2.993h2.5v-.998H342v.998zm9 .998h1v1.996c-.016.28-.11.514-.297.702-.187.187-.422.28-.703.296h-10c-.547 0-1-.452-1-.998v-10.976c0-.546.453-.998 1-.998h3c0-1.107.89-1.996 2-1.996 1.11 0 2 .89 2 1.996h3c.547 0 1 .452 1 .998v4.99h-1v-2.995h-10v8.98h10v-1.996zm-9-7.983h8c0-.544-.453-.996-1-.996h-1c-.547 0-1-.453-1-.998 0-.546-.453-.998-1-.998-.547 0-1 .452-1 .998 0 .545-.453.998-1 .998h-1c-.547 0-1 .452-1 .997z" fill-rule="evenodd"/></svg>'

  addButtons(
    '.hljs',
    button('Copy', 'Copy code to clipboard', copyIcon, 'btnClipboard'),
  )

  const clipboard = new ClipboardJS('.btnClipboard', {
    target: function (trigger) {
      return trigger.parentNode.querySelector('code')
    },
  })

  clipboard.on('success', function (event) {
    event.clearSelection()
    const textEl = event.trigger.querySelector('.btnIcon__label')
    textEl.textContent = 'Copied'
    setTimeout(function () {
      textEl.textContent = 'Copy'
    }, 2000)
  })
})
